Curtain airbag systems are intended to protect vehicle occupants in the event of a collision or other accident in two general ways. Firstly, in the event of, the curtain airbag provides cushioning for the head, shoulder, and upper body of an occupant between the side window grasps and/or the pillars and/or other side structure of the vehicle. Secondly, curtain airbags are intended to reduce the likelihood that the head, arm, or any other portion of the occupant may be forced out through the window opening during a crash event, whether the window glass is in the raised/closed position or the lowered/opened position.
In some vehicle applications, it may be desirable to position curtain airbags within or near the upper edge of a door or other side body panel of a vehicle so that the airbags deploy upward during inflation. Among the instances where this may be preferable are convertible-top vehicles, since the convertible may not provide adequate space for mounting an airbag or airbag module, and/or the convertible roof may be lowered or stowed so that a roof-mounted airbag will not be available to protect occupants. A door-mounted curtain airbag may also be preferred when styling or package constraints require a slim side roof rail.
In vehicle applications where the airbags are positioned within the door, it is advantageous for the curtain airbag to have geometry such that the occupant is kept within the vehicle and also receives the level of cushioning required during a crash event. It also advantageous for the curtain airbag to be constructed in such a manner that the packaging space and material required is at a minimum.